Joseph eli bertrand



UNITED STATES i PATENT OFFICE.

JOSEPH ELI BERTRAND, OF BOSTON, ASSIGNOR OF ONE-HALF TO MELLEN BRAY, OFNEVTON, MASSACHUSETTS.

SEWING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 502,874, 'dated August8, 1893.

Application iiled March 15, 1893. Serial N0.466,127. (No model.)

-Which the following, taken in connection with the accompanyingdrawings, is a specification.

My invention relates to sewing machines and particularly to that classof such machines as is used for sewing leather and to the devices fordrawing out the loop of .thread above the work and tightening thestitch, is an improvement upon the machine described in the LettersPatent No. 432,011, granted to me July 15, 1890, and it consists incertai-n novel features of construction, arrangement and'combi'nation of'parts which will be readily understood by reference to the descriptionof the accompanying drawings and toV the claim hereinafter contained,and in which my invention is clearly pointed out.

Figure l of the drawings is a vertical transverse section of a sewingmachine, in general substantially like that described in said priorpatent, the cutting plane being on an irregular line and showing theparts morepnearly relating to my presentinvention in elevation. Fig. 2is a front elevation of the loop uneasuring and stitch tightening fingerand its cari rier. Fig. 3 is a plan of said loop measuring and stitchtightening finger. Fig. 4 is a side elevation of the same. Fig. 5 is adiagram illustrating the position of the loop measuring and stitchtightening fingerwhen the loop of thread has been drawn out above thework and the needle is` in position to seize the upper thread, and Fig.6 is a similar view showing the same parts when the stitch has beentightened and the lock of the stitch drawn into the work.

In the drawings A is the bed plate of the' head of the machine, B is oneof the end frames, C the upper tie girt, D the cam or main operatingshaft mounted in suitable bearings in ksaid frames B, and E is the camfor operating the loop measuring and stitch tightening finger.

F is one of the two stands secured to the front of the bed A, inbearings in the upper shuttle carrier.

I is the work support, cis the needle guide, d is the loop opener, e thepresser-foot, J the presser-foot-har,f the thread tension wheel, g theratchet wheel connected to said tension Wheel, h the pawl and K the paWllever for locking said tension wheel, L the thread carrier for throwingthe thread into engagement with the barb of the needle a', and M thetake up lever. Y

So far 'the several parts except the cam E and the needle and awl areconstructed and arranged substantially as shown and described in saidprior patent before cited. In said prior patent the loop measuringfinger was pivoted to a reciprocating cross-h ead fitted to and movablein a grooveformed in the bed and arranged to vibrate about its pivotalconnection 'as it was moved toward and from the front of the machine,said looper nger serving only one purpose, that of measuring the lengthof loop of thread required for the needle to draw'throughY the work toform the loop below the work through which the shut- -tle was to pass,the stitch being drawn tight by the take-up lever. This arrangementWorked fairly Well but I have found by actual test, that, in order to.properly tighten the stitch and draw the lock of the stitch into thework so as to show a fair stitch on both sides of the work,.it is betterto apply the power, to do this, to the thread at a point much nearerthew work than the end of the take up lever. To eect this desirableobject is the aim of my present invention and to this end I construct,arrange, and operate the looper finger as Yshown in the accompanyingdrawings, in which N is the looper finger made in the form shown inFigs.2, 3, and 4 and having mounted in its hook end the small grooved wheelersheave vl thefgrooved 95 periphery of which engages the threadA to pullout the loop of thread above the work asl shown in Fig. 5.

The looper linger N is mounted in a socket in the cross-head O tted toand movable endwise in a dovetailed groove formed in the under side ofthe stand P bolted to, and pendent from, the tie girt C with its loweror grooved side oblique to a horizontal plane so that the finger N has aslight upward movement as it 1s moved toward the rear as shown in Fig.1.

B is a stand bolted to the rear edge of the bed A and having pivoted toits upper end the lever Q to the slotted lower end of which isadjustably pivoted one end of the link R, the opposite end of which ispivoted to the cross-head as shown in Fig. 1.

The lever Q has mounted on a stud set therein a truck j, shown only indotted lines in Fig. 1, which fits into, and is acted upon by, the path7c of the cam E to move said crosshead and the looper-finger toward andfrom the rear of the machine.

The cam E is dilferent from the cam for operating the looper finger inmy said prior patent in that besides the throw 7n for measuring the loopit is provided with the short outward and inward throws n and n betweenthe lines 1 and 2 and 2 and 3 respectively the throw n serving to movethe finger N backward a short distance, after the take-up lever hasdrawn up the slack of the lower loop, so as to tighten the stitch anddraw up the lock of the stitch into the work, the sheave or truck zengaging the thread between the work and the thread carrier L anddrawing it into the position shown in Fig. 6, this being done while thetension wheel f is locked by the pawl h and the take up lever M is heldfirmly,in the position shown in Fig. 1, by the cam for operating it, notshown in the drawings.

For information regarding parts of the machine not shown in theaccompanying drawings reference may be had to the before cited priorpatent.

The needle a and awl a2 are mounted in separate radius arms with theirpoints in opposite directions as shown and described in anotherapplication of mine, filed September 17, 1892, Serial No. 446,207.

The operation of my invention will be readily understood from theforegoing without further description here.

A great advantage is obtained by imparting the additional short throw tothe looper finger for drawing the lock of the threads into the work andtightening the stitch, and also by the employment of the sheave i on thehook end of the looper finger, by very much lessening the chang of thethread.

Vhat I claim as new, and desire to secure by Letters Patent of theUnited States, is-

In a sewing machine the combination with a work su pport and presserfoot, a needle and awl constructed and arranged to be recipro catedabout a common axis and a rotary shuttle, of a loop measuring and stitchtightening linger mounted in a reciprocating cross-head, a pivotedlever, a link connecting said crosshead to the movable end of saidpivoted lever, and a cam provided with a path having two outward and twoinward throws adapted to impart to said looper finger a long and shortrearward and forward reciprocation.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, on this 10th day of March, A. D.1893.

JOSEPH ELI BERTRAND.

Witnesses:

N. C. LOMBARD, H. T. CROSBY.

